Abstract: In order to prepare the SiC slurry for porous ceramics, the variation of the shear stresses and viscosities of SiC slurries with different mass fraction (40%-60%) were investigated.The results show that the isoelectric point of the slurry is about 3.6, and zeta potential value decreases with the increase of pH value, the dispersing effect of the slurry in the alkaline condition is better.The correlation coefficients are both above 0.98 by fitting the shear stresses of SiC slurries based on Casson equation.The limit viscosities and yield stresses increase with the increase of the mass fraction.When the shear rate reaches 100 s-1, viscosities of slurries with the mass fraction ranging from 40% to 55% are below 1 Pa·s.The viscosity of the slurry with the mass fraction of 60% is 2.1 Pa·s.

Key words: SiC slurry;rheological property;Casson model